Improvement in gear-cutting machines



4 -4Sheets-Sheet1. G. H. CORLISS. GEAR-CUTTING MACHINE. No. 190,470. Patented May 8,1877.

N. PETERSl PHDTO-LITMDGRPHER, WASHINGON, D C4 4 Sheets-Sheet Z. G. H. CGRLISS.

' GEAR-CUTTING MACHINE. N0. 190,470. Patented May 8,1877.

NA PETERS. PHOTUUTHDGRAPHER. WASHINGTON. D, C.

4 Sheets-Sheet 3.

Glv H. coRLIss. GEAR-CUTTING MACHINE.

Patented May 8,1877.

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N. PETERS. PHOTOLIITNOGRAPMERl WHXNGTON, DIC.

4Sheets-Sheet 4. G. H. CORjLISS. GEAR-CUTTING MACHINE.- -N- 190,470, Patented May a, v1877.

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i l y; W mum N. PETERS, PHDTQUTNOGRAPHER. WASHINGTON. D. C.

GEORGE H. OORLISS, OF PROVIDENCE, RHODE ISLAND.

IMPROVEMENT IN GEAR-CUTTING MACHINES.

Specilication forming part of Letters Patent No. 190,470, dated May 8, 1877; application tiled March 27, 1877.

To all w/wm yit may concern Be it known that I, GEORGE H. GORLISS, of Providence, in the State of Rhode Island, have invented certain new and useful Improvements relating to Gear Cutting Machines, of which the following is a specification:

The mode of operation of vmy improved machine is analogous to that of the machine set forth in the patent to me, dated March 10, 1849. The machine is adapted to cut bevelgears of large size, with. any required bevel, and gives the proper forms to each tooth, with the same contour of the tooth throughout. rIhe required outline is produced, not by a milling but by a planing` operation.

The planing-tool is guided by a' templet of sheet-steel or analogous material, previously c arefully wrought to the properform. The cuttlng-tool, as it is fed orintermittent-ly moved during the planing operation,is guided by the edge of that templet. 'Ihe planing-tool is carried on a slide, which is guided on a rigid trunk, which is adjustable at various inclinations, according to the bevel of the wheel re quired; but, instead of holding that adjustable bar or trunk by the end nearest to the large side of the wheel, I hold it at the center, or the point where the converging lines of the several teeth would meet. The improved machine also di'ers from that described in my former patent in the provisions for holding the cutting-tool, the provisions for operating it, the provisions for holding and adjusting the position of the wheel the teeth of which are to be cut, and in various other points, including provisions for more exactly adjusting and confining the wheel as it is successively turned and held for the several teeth to be cut.

My machine cuts, like its predecessor, one side ofeach tooth first; it is then readjusted, and various parts, including the templet, are 'reversed in position to dress or cut the other side of each tooth.

The following is a description of what I consider the best means of carrying out the invention.'

The accompanying drawings form a part of this specification.

Figure 1 is a side elevation, partly in section. Fig.2 is a front elevation', partly in section; and Fig. 3 is a rear view ofsome oi' the principalparts. Fig. 3a is a cross-section of a portion on the line s s in Fig. l. The wheel in Fig. 3 is broken away to allow the section Fig. 3a, and the parts beyond thes'ectiomto be seen in an approximately correct position relatively thereto. Fig. 4 is a plan view of the -machiue with certain parts removed. Fig. 5

represents the templet detached. This is on a much larger scale than the figures previously referred to. The succeeding ligures represent details detached, also on a large scale. Fig. 6 is a side elevation ot' the peculiar rack by which the slide carrying the cutting-tool receives motion. Fig. 7 is a crosssection of the same. Fig. 8 is a plan view of the device by which the proper end motion is communicated to the belt-shifter at the end of each movement of the cutting-tool.

' Similar letters yof reference indicate lik parts in all the tigures.

A is a tixed framing of cast-iron, forming an unyielding support for all the parts. Portions will be designated by further marks A1 A2, &c. on the ground or a suitable flooring by bolts, as represented. The looring must allow the large index-wheel to extend below it, and also allow the gear-wheel which is to be cut to similarly extend below when required.

An important portion of the rigid framing I denominate a quadrant.7 It is double, or formed in two parts, parallel to each other, (marked A1 A1.) An upright, A2, stiffens the upper end of the quadrant. y

rIhe wheel to be cut, or rather the rim on which the principal work is to be bestowed, and which, in this case, is made separately from the center, is marked W. (Sec Fig. l.)

It is bolted upon a conter piece, w, which isl bolted lirmlyupon a large arbor, X, supported in a long bearing in the framing, and formed withaseries of encircling grooves, w, which receive the gear-wheel Y, (shown in dotted outline,) mounted on a shaft, y, and adapted to be turned by a crank, (not represented,) to adjust the position ofthe arbor axially. Z is a large index-wheel, set adjustablybut rigidly upon the arbor X, and by turning which thev several teeth of the wheel W are successively The framing is firmly held down uppresented to be treated, as will appear further.

The cutter is guided by a stout and rigidly straight trunk, B, which turns on an axis, T2, which is at right angles with the axis of the arbor X. This trunk B is capable of being swung or turned up and down nearly the whole range of the quadrant A1, according as the wheel is required to be beveled at dii'erent angles.

D, Fig. l, is a slide, which embraces the trunk B and carries the tool d. D1 is a rack, forming, practically, an extension ofthe slide D. The teeth d of this rack D1 are each capable of swiveling'slightly, in order to accommodate themselves to a slight lateral swinging of the trunk B, which will be described farther on.

'E is a spur-gear wheel, mounted on a shaft, e, Fig. 2, and engaging with the teeth d', to operate the slide D, and consequently the cutter d. The shaft e is driven by gearing operated by reverse belts on fast and loose pulleys in a manner analogous to ordinary planing-machines. These parts are clearly shown in Fig. 2. The slide D, and consequently the cutter d, is moved backward and forward to dress the bevel-gear by a process analogous to planing, but guided to give the desired contour to the teeth.

The union of the trunkBwith its axis is effected by a universal joint. It is stiff in the direction to prevent the trunk B from twisting, but allows it to swing up and down and laterally, as required.

Each cut of the planing-tool d is in a line directly to and from the center Where the axis T2 crosses the axis ofthe arbor X a0.

The genera-l position or inclination of the trunk B having been determined according to the inclination of the bevel of the teeth, the upper end must be raised and lowered in planing' each tooth to an extent corresponding to the depth of the teeth, and it must be moved laterally to au extent corresponding to the width of the tooth, or half the tooth.

In practice I plane only one side or half of each tooth at one operation, and after planing the corresponding side of every tooth, I readjust the mechanism and plane the other side of each. I

Mechanism is mounted adjustably on the quadrant to control the movement of the outer or upper end of the trunk B during the dressing of a tooth. A templet, m, is prepared, as indicated in Fig. 5, and the projection'from the trunk B is caused to traverse slowly along its curved edge.

Two ropes are employed, which, by means of weights, (not shown,) exert constant force on the trunk. The rope b1, running over a pulley, b2, as shown, tends to balance the weight of the trunk B and its connections. The rope b3, running around three pulleys, b4 b5 bs, and carrying a weight, (not represented,) exerts, through the lever O, pivoted on a center fast on the quadrant A1 A1, a constant lateral force on the trunk B, tending to move it sidewise and hold it firmly against the edge of the templet.

The slide D may be required to traverse to various extents,`according as the gear-wheel to be cut is wide or narrow, and the tool d may be required to be set in dii'erent parts of the slide D, according as the wheel is large or small. I provide a series of holes with suitable holding means adapted to receive the cutter d at dierent points in the slide D. I can furthermore adjust the operating of the slide D, itself, further up and down or out and in on the trunk B, the rack D1 being suficiently long to allow of such adjustment within wide limits.

The reversing of the motion of the slide is effected by means analogous to that by which ordinary planing-machines are reversed. An

arm, D2, Fig. 1, extending from the slide D, l

embraces a rod, H, lying parallel to the direcf tion of the motion, and carrying adjustable stops h1 h2. This rod is connected to an arm, L, Figs. l and 2, turning loosely on the extended end of the shaft e, or, preferably, as shown, on a center otherwise firmly held in thesame line, equipped with the usual adjustments, and with means for changing the driving-belts M1 M2, respectively, from the fast Y vand loose pulleys, as the arm lis thrown in one direction or the other. The means by which this is eifected is shown with tolerable clearness in Figs. l and 2. The arm l extends from the lever L beyond the center or pivot of its motion, and works, as a 4lever ofthe second order, in a peculiar slot, N1, Fig. 8. This gives an end motion to the rod N, and thus moves the arms N2 N3, which embrace the belts M1 M2. There is, preferably, a roller on the end of the arm Z to work in the slot N1.

The end movement of the rod H at each termination of the movement of the slide D not only ships the belts and reverses the m0- tion of the slide, and induces the proper feeding downward of the trunk B to put it in position for the next eut, but also swings the trunk B and its connections, so as to hold the tool slightly out of contact during the return motion.

Both these movements are effected from the single rocking shaft G, which is rocked by means of the arm G1, pivoted to the rod H.

There are two other arms, G2 G3, on this rocking shaft. The arm C2 operates the feeding down, and the arm C3 operates the holding oi of the tool during the return motion. I will describe these motions separately, and first the feeding down.

F is a stout piece of framing adjustable in any required position on the quadrant A1, and held by hooked bolts, Fig. 3a. A rack, f,

thereon, Fig. l, receives the teeth of a pinion, g, which is operated by a large geanwheel, Gr, which receives motion from a pinion, g', turned intermittently through the action of a ratchetwheel on the same shaft turned by a click on .its action upon the arm the lever G1. This lever is actuated by a link, G2, which gets a reciprocating motion from the arm G2.

Next, the holding away ot' the tool. I is an varm smoothly rounded and hardened, and

adapted to bear delicately but firmly against the edge of the templet m. This arm I turns on a pivot, i, in the end ofthe trunk B. The other end of the arm I isbeveled, as shown in Fig. 3a, and is controlled in position by a slide, J, (see Figs. 1 and 3%) which is pivoted to the arm G3. A spring, K, Fig. l, holds these parts I and J in intimate contact in a recess provided, so that the rocking of the shaft G alternately in one direction and the other, when the tool d reverses its motion, also by the end movement of the part J and I, turns the arm I slightly upon the pivot t', and swings the entire trunk B sufficiently.

There are two of the pulleys b4 adapted to allow the rope b3 to be so reversed as to pull the trunk B either way, according as one side or the other of the teeth is being dressed.

It will be understood that the templet m must be turned over or shifted in position when the opposite sides of the teeth are to be dressed. This mechanism and its relation to thc double quadrant is clearly shown in Fig. 4 and in Figs. l and 3a.

Variations in the hardness of the metal, as well as in the depth ot' cut required indifferent portions of thewheel, make it important to provide means for not only turning the arbor X with exact mathematical accuracy in preparing to cut the next tooth, but also for holding it against any springing. I have provided for this as follows:

The edge of the wheel Z is toothed, and receives the teeth of a pinion, P, Fig. 3, supported in a bearing on the fixed framing and turned by a hand-wheel, p. There are series of equidistant holes around the periphery of the wheel Z. A pin, Q, is shifted by hand, as required, from one hole to the next, or to the alternate second or third or other hole, as may be previously determined, according to the number of teeth. Now, in order to turn and hold the wheel Z with. the required accuracy and' force, I turn until the pin Q is brought into contact with the upper edge of a thin, but sufficiently stout, stop-plate, B. When the wheel has been turned to bring the pin Q into firm contact -with the upper edge of the stop R it is clamped by a strong clamp, S.

When a wheel is bolted Yon the arbor it is not easy to setit with its teeth in exact relation to the holes in the periphery of the wheel Z. I can accommodate that by moving the stop B up or down a little after the wheel has been lxed to the arbor. This is el'ected by mounting the stop R on a slide, R', carried in guides on the framing, and operated by gearing from the hand-wheel T, as indicated in Figs. 3 and 4.

Inl order to easily and certainly insure uniform and just sufticiently forcible Contact of the pin Q with the upper edge of the stop B., I have further provided a slotted hooked piece, U, operated by a nut, V, to which a wrench may be applied. 0n nishing the treatment of one side of a tooth the wheel Z may be turned backward a little to bring the pin Q out of its'previous firm contact with the stop It and allow its removal. This pin is then removed and shifted to another hole, still within the slot in the piece U, Which slot must be made long enough to accommodate the greatest pitch which the machine will ever be required to cut. On turning the wheel Z bythe hand-wheelp, acting through the pinion P, until the pin Q is brought down into a loose contact, or an approximate contact, with the stop R, I swing the slotted hooked piece a little, after engaging the pin Q in the hooked end ofthe slot, operate the nut V, and draw Q into very firm contact. This is done before the tightening of the clamp S. Of course, on liberating the parts to turn the wheel again, the nut V must be slackened, to allow the slotted hooked piece U to be disengaged again.

Aside from the facilities which this form of the framing and general arrangement gives for using a large wheel, Z, and the several improved details of the mechanism, I esteem this construction intrinsically superior to my former machine, in the fact that the trunk B, which carries the slide, is firmly held at the apex of the cone, to which the lines converge. The old construction held the wheel to be cut in a horizontal plane, and held the guide or trunk (corresponding to my trunk B) only at the lower end. The upper end, toward which the lines converge, was left unsupported and liable to spring. The present machine is very rmly held at that point by a universal joint.

The construction of thatjoint is shown quite clearly in Figs. l scription may be of service. A casting, T1 T2, Fig. 2, is employed having two parts standing at right angles. The lower or horizontal arm T2 is adapted to turn in the framing A, and supports the shaft e in its central line, with liberty to turn freely in one direction, and the other to operate the tool d. The other arm, T1, (represented in Fig. 2'as upright,) is smoothly turned on its exterior, and stands within a corresponding cylindrical or slightly-tapered hole bored in the trunk B. The work forms a universal joint by the turning ot' the casting T1 T2 in the horizontal bearings, to allow the trunk to be raised and lowered, and by the turning of the trunk B itself in its bearing on the upright arm T1 of the part T1 T2, to allow the trunk to move laterally. v

I claim as my improvement in gear-cutting machinesl. The guiding bar or trunk B, jointed to the framing in line with the axis ofthe arbor and 2, but additional de- X, in combination with mechanism for taking hold of and guiding said bar at its opposite extremity, as herein specified.

2. The bar or trunk B and cross-shaft e, crossing each other at the center of the universal joint Tl T2, in combination With the quadrant A1 A1, as herein specified.

3. rEhe rack D1, having the swivel-teeth d', in combination with the operating-shaft, toolearrier D, and its guiding mechanism, with the arbor X, supporting the wheel to be cut, as herein specified. Y

4. The grooved arbor X, supporting the index-Wheel Z, and adapted to hold the Wheel to be cut, in combination with the operatingpinion Y, and with the reciprocating tool d and its operating means, guided by the adjustable bar or trunk B, as herein specified.

5. The adjustable stop R, in combination with the pin Q on the index-Wheel Z, and with means for turning the latter, as herein specil fied.

6. The hooked piece U, in combination with the stop R, Wheel Z, and with suitable gearcutting mechanism, as herein speciiied.

In testimony whereof I have hereunto set my hand this 28th day of September, 1876, in the presence of two subscribing witnesses.

GEO. H. GORLISS. [L. s]

Witnesses:

GEO. A. DODGE, GEO. W. KENNEDY. 

